Ascorbic acid microencapsulation by spray‐drying in native and acid‐modified starches from different botanical sources

Abstract

Native starches (NS) of maize (M), potato (P), and rice (R) were subjected to mild acid treatment for producing modified starches (ModSs). NRS and all the ModS were used for microencapsulating ascorbic acid (AA) by spray‐drying. AA retention %, surface AA %, AA stability, particle size analysis, glass transition‐water activity behavior and morphology of the microcapsules were studied. NRS microcapsules resembled “popcorn” balls of starch granules bound together by protein bridging. ModS microcapsules morphology was characterized by individual starch granules with differing particle size distribution. NRS microcapsules exhibited the initial lowest AA retention % and lowest surface AA %, but also suffered the lowest AA degradation upon storage. Among the ModS microcapsules those made with ModMS showed significantly lower AA degradation during storage. AA stability was closely associated to surface AA %. Peaks in glass transition temperature (Tg) occurred for ModPS and ModMS microcapsules at water activity (aw) of ∼0.34, and for the ModRS microcapsules at aw of ∼0.42. The NRS microcapsules exhibited a monotonous decrease in Tg with increasing aw values. Based on these results storage stability conditions were set at aw = 0.328 ± 0.002 and 25°C, in order to minimize the structural changes of all the starch matrices with storage time.

Using Modified Starch/Maltodextrin Microparticles for Enhancing the Shelf Life of Ascorbic Acid by the Spray‐Drying Method

“…The resulting mixture was homogenized with vortex equipment and immediately fed into the spray‐dryer (Mini Spray Dryer B‐290, BUCHI Corporation, New Castle, DE). The liquid flow rate, and the inlet and outlet air temperatures were maintained at 7 mL min −1 , 160 °C and 110 °C, respectively . Experiments were performed in triplicate.…”

“…In addition, the use of maltodextrin for the encapsulation of anthocyanins produced protective microcapsules with a slight decrease in the anthocyanins content after 10 weeks . Recent studies have reported the microencapsulation of AA by spray‐drying, using different wall materials either one at a time or in combination . The effects of the wall material on microencapsulation efficiency, stability during storage, controlled release rates, and AA bioavailability were characterized …”

“…Recent studies have reported the microencapsulation of AA by spray‐drying, using different wall materials either one at a time or in combination . The effects of the wall material on microencapsulation efficiency, stability during storage, controlled release rates, and AA bioavailability were characterized …”

“…It has been reported that the ratio of amylose/amylopectin has an important effect on encapsulation capacity and that the size of the starch granules has a decisive role in the capacity for protecting AA after 30 days of storage . Recently, Palma‐Rodriguez et al reported that the acid modification of rice starch increased the retention values for AA after 15 days of storage compared with its non‐modified counterpart. It was suggested that, to enhance the efficiency and retention capacity of active compounds, tight control of the starch modification method (chemical, physical, or enzymatic) is required.…”

Acetylation of normal and waxy maize starches as encapsulating agents for maize anthocyanins microencapsulation

“…Anthocyanins from Corozo (Bactris guineensis) encapsulated with maltodextrins were largely affected by the environment's humidity (>76%) (Osorio et al, 2010). On the other hand, starches modified by acid hydrolysis have shown good encapsulating properties (Palma-Rodriguez et al, 2013;Spada et al, 2012). For increasing the stability of the encapsulated anthocyanins, it is desirable to have low moisture absorption.…”